✅ Ratchet up the minimum coverage requirements

.github/workflows/test.yml

@@ -38,7 +38,11 @@ jobs:
       timeout-minutes: 5 # _should_ finish in under a minute
 
     - name: Report coverage
-      if: ${{ matrix.os == 'ubuntu-latest' && github.event_name != 'pull_request' &&
-        !startsWith(matrix.ruby, 'truffleruby') && !startsWith(matrix.ruby, 'jruby') }}
+      if: ${{ matrix.os == 'ubuntu-latest' &&
+        github.event_name != 'pull_request' &&
+        matrix.ruby != "ruby-head" &&
+        !startsWith(matrix.ruby, 'truffleruby') &&
+        !startsWith(matrix.ruby, 'jruby') }}
       run: bundle exec rake coverage:report
       timeout-minutes: 1 # _should_ finish in under a second
+      continue-on-error: true

.simplecov

@@ -1,8 +1,6 @@
 # frozen_string_literal: true
 
 SimpleCov.configure do
-  formatter SimpleCov::Formatter::HTMLFormatter
-
   enable_coverage  :branch
   enable_coverage  :method
   enable_coverage  :eval

Rakefile

@@ -12,13 +12,63 @@ end
 
 task :default => :test
 
-desc "Output coverage data report, and error when threshholds aren't met"
+desc "Output HTML coverage data report, and error when threshholds aren't met"
 task "coverage:report" do
   require "simplecov"
   SimpleCov.collate "coverage/.resultset.json" do
+    formatter SimpleCov::Formatter::HTMLFormatter
+
     coverage(:line) do
-      minimum           90
-      minimum_per_file  40
+      minimum           95
+
+      minimum_per_group 98, only: "Config"
+      minimum_per_group 97, only: "StringPrep"
+      minimum_per_group 97, only: "SASL"
+      minimum_per_group 95, only: "Data Types"
+      minimum_per_group 94, only: "Parser"
+      minimum_per_group 92, only: "Client"
+
+      minimum_per_file  90
+      minimum_per_file  87, only: "lib/net/imap/sasl/authenticators.rb"
+      minimum_per_file  86, only: "lib/net/imap/config/attr_type_coercion.rb"
+      minimum_per_file  84, only: "lib/net/imap/authenticators.rb"
+      minimum_per_file  80, only: "lib/net/imap/response_data.rb"
+      minimum_per_file  55, only: "lib/net/imap/search_result.rb"
+    end
+
+    coverage(:branch) do
+      minimum           80
+
+      minimum_per_group 92, only: "Data Types"
+      minimum_per_group 87, only: "Config"
+      minimum_per_group 83, only: "Client"
+      minimum_per_group 81, only: "Parser"
+      minimum_per_group 76, only: "SASL"
+      minimum_per_group 73, only: "StringPrep"
+
+      minimum_per_file  65
+      minimum_per_file  62, only: "lib/net/imap/sasl/scram_authenticator.rb"
+      minimum_per_file  50, only: "lib/net/imap/sasl/authenticators.rb"
+      minimum_per_file  50, only: "lib/net/imap/config/attr_accessors.rb"
+    end
+
+    coverage(:method) do
+      minimum            88
+
+      minimum_per_group 100, only: "Config"
+      minimum_per_group  92, only: "Data Types"
+      minimum_per_group  90, only: "StringPrep"
+      minimum_per_group  88, only: "Client"
+      minimum_per_group  83, only: "Parser"
+      minimum_per_group  82, only: "SASL"
+
+      minimum_per_file   66
+      minimum_per_file   64, only: "lib/net/imap/response_parser/parser_utils.rb"
+      minimum_per_file   57, only: "lib/net/imap/sasl/authenticators.rb"
+      minimum_per_file   50, only: "lib/net/imap/authenticators.rb"
+      minimum_per_file   50, only: "lib/net/imap/sasl/anonymous_authenticator.rb"
+      minimum_per_file   36, only: "lib/net/imap/sasl/protocol_adapters.rb"
+      minimum_per_file   20, only: "lib/net/imap/response_data.rb"
     end
   end
 end

test/lib/helper.rb

@@ -3,6 +3,10 @@
 
   require "simplecov"
 
+  # run `rake coverage:report` for HTML/JSON formatter
+  require_relative "simplecov_markdown_table_formatter"
+  SimpleCov.formatter = SimpleCovMarkdownTableFormatter
+
   SimpleCov.start do
     command_name "Net::IMAP tests"
   end

test/lib/simplecov_markdown_table_formatter.rb

@@ -0,0 +1,88 @@
+# frozen_string_literal: true
+
+require "simplecov"
+
+# This formatter is much faster than the HTML formatter, and it prints much more
+# useful info to stderr than any of the bundled formatters.
+#
+# TODO: extract this to its own gem?  it needs some basic tests
+# TODO: output to ENV["GITHUB_STEP_OUTPUT"]
+class SimpleCovMarkdownTableFormatter < SimpleCov::Formatter::Base
+  def format(result)
+    return if @silent
+    output = "### Coverage report for #{result.command_name}\n"
+    output << format_markdown_table(result)
+    $stderr.puts output
+    output
+  end
+
+  def format_markdown_table(result)
+    groups = { "All files" => result }.merge(result.groups)
+      .transform_values(&:coverage_statistics)
+
+    name_size = groups.keys.map(&:length).max
+    criteria_sizes = groups
+      .values.map { _1.transform_values(&:total) }     #=> Array[Hash[name, total]]
+      .reduce { _1.merge(_2) {|_, a, b| [a, b].max } } #=> Hash[name, max]
+      .transform_values { _1.to_s.length }             #=> Hash[name, strlen]
+
+    rows = format_markdown_table_header(name_size, criteria_sizes)
+
+    rows.concat groups.map {|name, stats|
+      format_row_cells(name, stats, name_size, criteria_sizes)
+    }
+      .map { format_markdown_table_row _1 }
+
+    rows.join("\n")
+  end
+
+  private
+
+  def format_markdown_table_header(name_size, criteria_sizes)
+    heading_cells = format_markdown_table_row([
+      "Group".center(name_size),
+      *criteria_sizes.map {|name, size|
+        "#{name.to_s.capitalize} coverage".center(column_width(size))
+      }
+    ])
+    border_line = format_row_cells("", name_size, criteria_sizes)
+      .then { format_markdown_table_row _1 }
+      .then { _1.tr(" ", "-") }
+    [heading_cells, border_line]
+  end
+
+  def format_markdown_table_row(cells) = "| #{cells.join(" | ")} |"
+
+  def format_row_cells(name, stats = {}, name_size, criteria_sizes)
+    name = name.ljust(name_size)
+    cols = criteria_sizes.map {|criterion, size|
+      format_stat_column(stats[criterion], size)
+    }
+    [name, *cols]
+  end
+
+  def column_width(size) = 10 + size * 2 + 1 # "000.00% = " + 2*size + "/"
+
+  def colorize_percent(percent)
+    formatted = "%6.2f%%" % [percent]
+    color     = SimpleCov::Color.for_percent(percent)
+    SimpleCov::Color.colorize(formatted, color)
+  end
+
+  def format_stat_column(stat, size)
+    if stat
+      "%%s = %%%{size}s/%%%{size}s" % {size:} % stat_values(stat)
+    else
+      ""
+    end
+      .ljust(column_width(size))
+  end
+
+  # converts SimpleCov::CoverageStatistics to [String, String, String]
+  def stat_values(stat)
+    return ["0", "0", colorize_percent(0.0)] unless stat
+    percent = colorize_percent SimpleCov.round_coverage(stat.percent)
+    [percent, stat.covered, stat.total]
+  end
+
+end